An Afghan policeman picked up a machine gun from the back of a pickup and opened fire on a group of U.S. soldiers and his fellow Afghan police officers.

The incident was the latest in a trend of insider attacks that have killed dozens of U.S. military personnel. It is Air Force Tech Sgt. Steven Ely's job to make sure airmen at Bagram Air Field are trained in case of such an attack.

Ely, 31, of Duncan, is a 12-year Air Force veteran. After high school, he tried college, attending classes at Southwestern Oklahoma State University in Weatherford.

“I wasn't the role model child. I grew up kind of rough,” Ely said Tuesday during a telephone interview from Afghanistan. “I didn't do so hot in school and was looking for some other options.”

Ely joined the Air Force, specializing in security forces. He has trained special reaction teams, the Air Force's version of a SWAT team, and Air Force snipers. As the threat of insider attacks grew, the Air Force needed someone like Ely to teach his fellow airmen how to react in case of an active shooter on base.

At a Senate Armed Services Committee hearing in November on the nomination of Marine Gen. Joseph F. Dunford Jr. to become commander of NATO troops in Afghanistan, Sen. Jim Inhofe, R-Tulsa, and Sen. Susan Collins, R-Maine, asked about the insider threats.

Collins said the killings were “absolutely devastating to the families of American service members since they are trying to train and help these Afghan forces … And I think that these attacks also are jeopardizing the willingness of our partners to continue their own missions in Afghanistan.”